Thyroid dysfunctions of prematurity and their impacts on neurodevelopmental outcome.

MedLine Citation:

PMID:
23412858
Owner:
NLM
Status:
MEDLINE

Abstract/OtherAbstract:

BACKGROUND: Thyroid dysfunction is very common and is associated with neurodevelopmental impairments in preterm infants.OBJECTIVES: This study was conducted to determine the incidence and natural course of various thyroid dysfunctions and their impacts on neurodevelopmental outcomes among premature infants.METHODS: A total of 177 infants were enrolled who were born at <34 weeks or whose birth weight was <1500 g and who underwent repeat thyroid function tests. We analyzed how various thyroid dysfunctions affected neurodevelopmental outcomes at 18 months of corrected age.RESULTS: Thyroid dysfunction was noted in 88 infants. Hypothyroxinemia was observed in 23 infants, and their thyroid function was influenced by variable clinical factors. Free T4 levels were all normalized without thyroxine medication, and neurodevelopmental outcomes were not affected. In contrast, hyperthyrotropinemia was not associated with other clinical factors. Among 58 subjects who had hyperthyrotropinemia, only 31 infants showed normal thyroid-stimulating hormone (TSH) levels at follow-up tests. The remaining 27 infants had persistently high TSH levels, which significantly and poorly influenced the neurodevelopmental outcomes.CONCLUSIONS: Thyroid dysfunction is common among preterm infants. With the exception of persistent hyperthyrotropinemia, it generally does not affect neurodevelopmental outcomes. However, the beneficial effects of thyroid hormone therapy in patients with persistent hyperthyrotropinemia merits further study.